In some fanfictions, Snape might have a change of heart due to his love for Lily Potter. This could lead him to explore ancient and forgotten magics. He might find a magic that can nullify Voldemort's immortality spell. He then spends time preparing himself, both magically and mentally. When the time is right, he challenges Voldemort in a one - on - one duel and, with his new - found magic and his determination, manages to kill the Dark Lord.
Another plotline might involve Snape turning some of Voldemort's Death Eaters against him. Snape could convince them that Voldemort's actions are leading them all to destruction. With a group of former Death Eaters on his side, Snape could plan a coordinated attack on Voldemort. He could use his knowledge of the Death Eaters' secrets and Voldemort's lairs to stage a surprise ambush and kill Voldemort in the chaos.
One possible plotline could be that Snape discovers a hidden vulnerability in Voldemort. Maybe it's related to his Horcruxes. Snape, being the intelligent and resourceful character he is, figures out a way to destroy all of Voldemort's Horcruxes without Voldemort suspecting. Then, he uses his powerful magic skills, perhaps a combination of dark and light magic, to directly confront and kill Voldemort.
Maybe Draco discovers a powerful magical artifact that can defeat Voldemort and he decides to use it for the greater good, even if it means going against his family's past allegiances. He could then face many challenges and battles before finally being able to kill Voldemort.
One interesting fanfiction could be 'Snape's Redemption: Voldemort's End'. In this fic, Snape uses his deep knowledge of the Dark Arts against Voldemort. He discovers a long - forgotten spell that can counter Voldemort's main source of power. It's a really exciting read as it shows Snape's cunning and his determination to finally put an end to Voldemort's reign of terror.
One possible plotline could be that Snape remains a loyal Death Eater throughout. He continues to carry out Voldemort's orders without question. Maybe he helps Voldemort in his search for more powerful dark magic, and in this version, he has no hidden motives of protecting Harry or the Order. He is fully committed to the Dark Lord's cause, which could lead to a much darker and more hopeless situation for the wizarding world.
One possible plotline could be that Snape discovers a hidden weakness of Voldemort. Maybe through his years of spying, he finds out that a certain spell, when combined with an ancient magic artifact, can destroy Voldemort. So he devises a plan to get hold of the artifact and uses the spell at a crucial moment when Voldemort is off - guard, perhaps during a major battle when Voldemort is focused on other opponents.
After Harry kills Voldemort in the graveyard in the fanfiction, the magical balance might shift. With Voldemort gone, some of the dark magic that was prevalent might start to fade away. The Hogwarts School of Witchcraft and Wizardry could see a new golden age. New spells and magical theories might be explored as the fear of Voldemort no longer holds back the wizarding scholars. Harry himself might start to travel around the world to spread the news of Voldemort's defeat and also to learn more about different types of magic. His friends would also have new opportunities, like Hermione might be able to further her studies without the constant threat of Voldemort and Ron could finally relax and enjoy a more peaceful life at the Burrow.
The wizarding world would likely be in a state of shock and then celebration. People would start to see Azkaban in a new light, perhaps no longer as just a place of horror but also as the site where the great evil was finally vanquished.
In some fanfictions, Snape might be working with Voldemort because he has been blackmailed. Voldemort could have found out some deep, dark secret about Snape and is forcing him to cooperate. This could be related to Snape's past or something he has done that he doesn't want to be made public.
Yes, it could be possible in fanfiction. Fanfiction allows for wild reinterpretations of the source material. Maybe there could be a story where a dark wizard in the past manipulated their family trees so that Harry, Snape and Voldemort are unknowingly brothers. It would make for a very interesting plot, full of drama and conflict as they are on different sides in the original story.
Well, perhaps Pettigrew gets tired of living in fear under Voldemort. He might find a powerful magical artifact that has the potential to kill Voldemort. As he tries to steal it for himself, Voldemort discovers his plan. In the ensuing struggle, Pettigrew manages to turn the artifact against Voldemort and kills him. This would then lead to Pettigrew having to deal with the consequences, like facing the wrath of the Death Eaters who are still loyal to Voldemort.
Well, in some fanfictions like this, it might be due to a dark magic curse that controls Harry's mind and makes him do it. However, this is a very dark and non - canon concept.